A device executing a start-up control method for an electric scroll compressor has a thermistor (18) and a pressure sensor (20) which, prior to the start-up of the scroll compression unit, detect temperature and pressure of a suction refrigerant introduced into the compression unit (2), and a controller (10) for controlling driving of a motor (4) of the compression unit (2) at the start-up of the compressor. The controller (10) determines at the start-up of the compressor whether or not a liquid refrigerant exists in the compression unit (2) on the basis of the detected temperature and pressure; selects either a normal start-up mode or a liquid-discharge mode in which the rotational speed of the motor (4) is regulated to be lower than in the normal start-up mode, according to the determination result; and controls the start-up of the compression unit (2) through the motor (4) according to the selected mode.