Abstract: Apparatus and method of the invention are used for cleaning a hollow member such as a heat exchanger. A cleaning device is formed of a cleaning member holding section having a transfer passage for receiving cleaning members therein, a cleaning member guide, a fluid introduction guide having a passage for introducing a fluid, and a direction changing member. The cleaning member guide has a guide passage for guiding one of the cleaning members into the hollow member, and an inserting portion formed at the front end to be inserted into the hollow member. The direction changing member is connected to the transfer passage, the rear end of the cleaning member guide and the fluid introduction guide and includes a receiving portion therein. The direction changing member selectively takes a first or second position.