Camera:
Still motion photography is the means in which most evidence of ghostly activity is obtained. In all honestly, any camera will do. The one most frequently used are Digital cameras.

Electro-Magnetic Field Detectors:
EMF detectors are a must have among Ghost Hunting. Their purpose is to detect the presence of electro-magnetic fields. EMF fields can be generated by ghosts and has been related to haunting activity. HOWEVER, all electronic devices, live wires, uderground wires, and solar activity (sun flares/solar storms) also generate EMF's. As a note, a Compass does the same thing as the EMF detector.

Thermal Scanner:
A more expensive alternative to the digital thermometer, the thermal scanner uses infrared technology to instantly detect temperature differences at a distance. You can expect to spend about $200 for a good one. This too is an awesome tool.

Video Camera
Obvious reasons!!!!

Thermal Imaging Scopes:
detects a temperature anomaly directly in front of your team. Thermal Imaging Scopes will allow you the luxury of actually seeing what your thermal scanner sees. Using infrared technology, you can actually see the shape and size of that cold spot. The fire departments use this to see "hot spots" in house fires that they have extinguished. These are awesome tools, but very, very expensive.

Audio Recorder:
Ghost hunters have come to know that ghosts are able to leave little tidbits of their existence called EVP's on audio tape. Otherwise known as electronic voice phenomena or EVP. We personally use a digital voice recorder. It takes the same kind of memory card that our digital cameras have. And when we want to render the audio on to our computer, it's just plug and play.  Software such as GoldWave can then be used to filter out the noise and render our EVP's audible to the human ear.  As a side note, an external microphone is recomended.  Reason being, the gears inside the tapeing device can be heard during EVP capture.  This just adds to the other noises that need to be filtered out.  It's best to just avoid that by using an external mic.

Motion Detectors:
Motion detectors can alert you to movement in an area where there should be none. Easily, an entire room or hallway can be monitored with just one device. This is a great indoor tool that doesnt need monitoring. Usually you can set these up and go about your business.  If somthing sets the alarm off you can them come back to that area and investigate further.