A construction machine where a load acting on a vehicle body during an operation is transferred to ensure the strength of the vehicle body, thereby improving reliability including welding reliability. In the construction machine, at least one of the height differences between an upper face or a lower face of the center frame at a joining portion between the center frame and the connecting member and an upper face or a lower face of a center joining portion of the connecting member is set respectively at a dimension that is approximately equal to or less than the thickness of an upper face plate or a lower face plate of the center frame.