Provided is an excellent residual gas analyzer, which can perform measurements while being suitably arranged even in small areas, such as those in semiconductor equipments, and can perform measurements for display of measurement results without an external personal computer. The analyzer is provided with a sensor unit having a sensor section for detecting a residual gas; an operating section for receiving operation for controlling the sensor section; a residual gas analysis processing section for processing analysis of the residual gas based on the output from the sensor section; and an analysis processing result screen display section for displaying on a screen the analysis processing results obtained from the residual gas analysis processing section. The analyzer is also provided with a device main body which can be in a mounted status wherein the sensor unit is mounted or in a removed status wherein the sensor unit is removed.