To reduce work effort for maintenance and inspection work of a rotary regenerating heat exchanger and enable sure and efficient execution of the work, by providing a means for remote-controlling a valve for starting and stopping operation provided in an air line for supplying air to an air motor.

In ordinary operation, a main valve 7a and operation valves 7b, 7c are opened, a bypass valve 7d and operation valves 7f, 7g are closed and a solenoid valve 7e is opened in an air line to an air motor 6. In maintenance and inspection work, the main valve 7a is opened, the operation valves 7b, 7c are closed, the solenoid valve 7e is closed and the operation valves 7f, 7g, 12, 15 and a main valve 21 are opened, and switching to operation by instrument housing box 8 is carried out. That is, the operation box 19 is operated so as to open a solenoid valve 10 and air is fed to the air motor 6, and valve opening of a rotation speed regulating control valve 11 is controlled so as to regulate rotation speed of a rotor, and maintenance and inspection work are effected.