A vacuum pump apparatus has a casing and a base connected to the casing. The base has an opening communicating with an interior space of the casing. A heater is mounted on the base for heating the base to maintain a gas discharge path at a temperature high enough to prevent solidification of processed gas in the vacuum pump. A cover member covers the opening of the base. The cover member has a first surface communicating with the interior space of the casing and a second surface exposed to the exterior of the vacuum pump. A substrate is connected to the first surface of the cover member and has at least one circuit for controlling operation of the vacuum pump.