A mobile crusher includes: a crusher for crushing raw materials; a discharge conveyor provided on a lower stream of the crusher for discharging the raw materials crushed by the crusher; a work implement provided on an upper stream of the crusher for producing the crushed materials; a conveyor sensor and conveyor pressure comparing unit for determining whether the crushed materials to be discharged are fed on the discharge conveyor or not; a crusher pressure sensor and crusher pressure comparing unit for determining whether the raw materials are present in the crusher or not; and a flow rate controller for controlling the speeds of the crusher, discharge conveyor and work implement based on determination results of the conveyor pressure sensor, conveyor pressure comparing unit, crusher pressure sensor and crusher pressure comparing unit.