To execute works such as inspecting the residual quantity of engine oil which is frequently performed as daily inspection by easily opening an engine cover at a light force when the engine cover is not necessarily fully opened in performing a kind of work with an engine cover opened.

An engine cover 20 is divided into two, a first opening/closing cover 21 and a second opening/closing cover 22, the first opening/closing cover 21 is connected to a hood by a hinge 23 so as to be rotationally moved in the vertical direction, and the top face part of the second opening/closing cover 22 is connected to the top face part of the first opening/closing cover 21 in such a state as relatively rotationally moved toward vertical direction by a hinge 24. When only the second opening/closing cover 22 is opened by lifting, the top of an oil tank 61 in the engine 60 is opened and the residual quantity of the engine oil can be inspected through the inspection hole.