A hydraulic excavator (1) includes a wireless authentication device (52) performing wireless authentication with a portable key device (51) and a vehicle body controller (48) for starting an engine (15) based on authentication by the wireless authentication device (52) and an operation of a start switch (12). The wireless authentication device (52) transmits a request signal within an authenticable range and performs authentication when it receives an ID code for authentication replied from the portable key device (51) based on the transmitted request signal. The vehicle body controller (48) prohibits driving of a hydraulic actuator (5E, 5F, 5G, 5H, 2E, 2F, 3A) when the portable key device (51) is outside of the authenticable range even if a gate lock lever (13) has been switched to an unlock position.