NOVELTY - The pump has a pump chamber recess (1b) for defining a part of a pump chamber (P) on an end of a shaft support hole (1a). A metal stator case (3) accommodates a motor section including a motor stator (6) and a motor rotor (9) inside the stator case. A plastic circuit case part (4) is fixed to a part of the stator case that is opposite to a part to which a pump housing (1) is fixed. A circuit substrate (23) contains a capacitor (21) and a power transistor (22) to control activation of the motor section. The substrate is fixed to the case part and separated from the stator case.    USE - Aluminum alloy made electric pump for circulating vehicle oil.    ADVANTAGE - The circuit substrate is fixed to the circuit case part and separated from the case, so that heat of the motor stator is not easily transferred from the case directly to the circuit substrate when the circuit case part is formed of plastic, while easily dissipating heat of the motor stator from the stator case and the pump housing without high dimensional accuracy, thus preventing the capacitor and the power transistor from damaging by heat. The pump includes dissipation fins formed on a back surface of a small recess of a heat sink cover, so that the dissipation fins are prevented from increasing axial length of the pump and the dissipation fins improve dissipation performance. The pump ensures that connection between an introduction bore of the circuit substrate and a coil connecting portion of the motor stator can be visually checked via a through hole of the circuit case part in a state in which the heat sink is not mounted, so that operability of the pump is improved with improved connection reliability of coil connecting ends. The pump includes an aluminum made heat sink arranged side-by-side with an accommodating recess along direction orthogonal to a rotary shaft, so that size of the circuit case part is prevented from increasing to reduce size of the pump along the axial direction.    DETAILED DESCRIPTION - The motor stator is a stator of a brushless motor.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of an electric pump.    Pump chamber (P)    Pump housing (1)    Shaft support hole (1a)    Pump chamber recess (1b)    Metal stator case (3)    Plastic circuit case part (4)    Motor stator (6)    Motor rotor (9)    Capacitor (21)    Power transistor (22)    Circuit substrate (23)