A semiconductor device manufacturing method, includes: a preparing process for preparing a conductive plate, a semiconductor chip arranged over the conductive plate with a first bonding material therebetween, and a connection terminal including a bonding portion arranged over the semiconductor chip with a second bonding material therebetween; a first jig arrangement process for arranging a first guide jig, through which a first guide hole pierces, over the conductive plate, such that the first guide hole corresponds to the bonding portion in a plan view of the semiconductor device; and a first pressing process for inserting a pillar-shaped pressing jig, which includes a pressing portion at a lower end portion thereof, into the first guide hole, and pressing the bonding portion of the connection terminal to a side of the conductive plate with the pressing portion.