Abstract: An escalator comprises a plurality of treadboards, coupled with each other in the endless form, for conveying people thereon, a driving device for driving the treadboards, which has a driving mechanism, including an electric motor, for transmitting a driving force from the motor to the treadboards and a power converting unit for supplying electric power to the motor. Component devices of the driving device are categorized into two groups in consideration of heat generated in the respective component devices. Component devices, which are categorized into a group of heat generating devices, are installed in a machine room, and component devices, which are categorized into a group of heat sensitive devices, are installed in another machine room. The two machine rooms are arranged in different locations within an escalator frame, which are remote from each other in the direction of the length of the frame.