The invention provides an air-conditioning apparatus that maximizes the space in an operator's cab and provides a comfortable working environment for the operator of a construction machine. The body unit of the air-conditioning apparatus is disposed under the floor surface of the cab, cold air and hot air ducts are connected to the body unit, and routed under the floor of the cab to be passed through the floor surface and taken out into the inside of the cab using cold air and hot air outlets disposed at both left and right sides at the front part of the cab. Also, by providing two evaporators, air of different temperatures can be blown through the left and right outlets.