In an exhaust gas purifier provided in an engine, a filter regeneration control recovering a PM collecting capacity of filter means on the basis of a chemical reaction can be efficiently executed by a simple structure. An exhaust gas purifier in accordance with the present invention is provided with a particulate filter (50) for purifying an exhaust gas arranged in an exhaust path of an engine (5), an actuation portion hydraulic pump (101) driving on the basis of a power of the engine (5), a pressure sensor (68) capable of detecting a clogging state of the particulate filter (50), and a pressure control valve (104) and a switching solenoid valve (106) for forcibly increasing an actuation amount of the actuation portion hydraulic pump (101). The filter regeneration control increasing an engine load is executed by increasing a discharge pressure of the actuation portion hydraulic pump (101) in accordance with a pressure control of the pressure control valve (104) on the basis of detection information of the pressure sensor (68).