The invention relates to a semiconductor device (10) comprising an electrically conductive bottom plate (1) on an upper side of which a semiconductor element (2) is positioned with a first connection region and a second connection region and with a first conductor and a second conductor, part of which is connected to, respectively, the first and the second connection region of the semiconductor element (2), the semiconductor element (2) and the parts of the conductors connected to the semiconductor element (2) being provided with an electrically insulating resin encapsulation (4) that covers a side face of the bottom plate (1), and the side face of the bottom plate (1) being provided, at the bottom face of the bottom plate (1), with a cavity (5) which is filled with a part of the encapsulation (4). According to the invention, the cavity (5), viewed in a direction transverse and perpendicular to the edge of the bottom plate (1), has the form of a staircase with to steps. In this way it is achieved that during the formation of the encapsulation (4), which at this stage is still liquid, said encapsulation (4) overflows a part of the bottom face of the bottom plate (1). Thus, the resulting device (10) can be mounted flat and with excellent heat sink capability of the bottom plate (1). Preferably, the semiconductor device (2) comprises a discrete power device such as a (LD)MOSFET. The invention further comprises a cheap and easy way of manufacturing a device according to the invention.