A controller which controls an operation of a self-propelled mechanism of an endoscope includes an inspection control section, a usual control section, an endoscope connection detection circuit and a control switch section. The endoscope connection detection circuit detects that the endoscope has been connected. The control switch section determines whether or not the inspection operation is performed for the endoscope at the time of the connection of the endoscope, causes the usual control section to perform the usual operation when the inspection operation is performed, and causes the inspection control section to perform the inspection operation and then causes the usual control section to perform the usual operation when the inspection operation is not performed.