Substrate processing apparatus and substrate processing method

The present invention provides a substrate processing apparatus and a substrate processing method. A substrate processing apparatus 1 includes a processing liquid tank 30, a first circulation pipe 31, a filter 39, a pump 37, and a controller 3A. The first circulation pipe 31 has an upstream end 31a connected to the processing liquid tank 30 and a downstream end 31b connected to the processing liquid tank 30. A processing liquid circulates in the first circulation pipe 31. The filter 39 is deposed in the first circulation pipe 31 and captures particles contained in the processing liquid. The pump 37 is disposed in the first circulation pipe 31. The pump 37 includes a rotor 371 and feeds the processing liquid by rotating the rotor 371. In activation of the pump 37 in a stopped state, the controller 3A controls the pump 37 so that the rotor 371 rotates at a rotational acceleration of no greater than 400 rpm/sec.