In a backhoe comprising: a diesel engine able to increase a speed due to an accelerating operation; an exhaust gas cleaning device having a DPF for catching a particulate matter included in an exhaust gas exhausted from the diesel engine; and a filter regeneration means to combust and remove the particulate matter deposited in the DPF of the exhaust gas cleaning device, the filter regeneration means requires to increase the speed of the diesel engine during an automatic regeneration for automatically combusting and removing the particulate matter deposited in the DPF. In this manner, a working machine able to require an operator to increase the speed of the diesel engine at appropriate timing, in order to increase a temperature of the exhaust gas to a temperature required for regeneration of the DPF can be provided.