An electric linear actuator has a housing with an electric motor mounted on the housing. A speed reduction mechanism and ball screw mechanism converts rotational motion to axial linear motion. A nut is rotationally but axially immovably supported by bearings on the housing. A screw shaft is coaxially integrated with the drive shaft. The shaft is inserted into the nut, via helical grooves and a large number of balls. The screw shaft is non-rotationally supported on the housing but is axially movable. The housing has a first housing and a second housing arranged with their end faces abutting against each other. Joining surfaces of the end faces of the first and second housings are sealed by a curing liquid curable material.