u2212 layer 20 in this embodiment since apertures 28 are provided in the n buried layer 12 the accumulated holes 35 are discharged outside not only via a path toward the anode but also via another path from the apertures 28 in the n buried layer through the p type silicon substrate 11 p buried layer 30 and p diffusion layer 31 to the gnd electrode 027 the latter path is illustrated by arrows in fig1 as a result the accumulated carriers 35 are quickly swept out and thereby a lateral diode having superior switching characteristics recovery characteristics is achieved in addition advantageously it can be expected that current through the path involving the anode or cathode is decreased because the hole current 42 is discharged also via a path through the p type silicon substrate 11 as described above according to this embodiment apertures 28 provided in the n buried layer 12 serve to quickly sweep out accumulated carriers into the substrate 11 side and thereby the recovery characteristics can be improved the shape size and number of the apertures 28 may have different variations fig4 to 9 are schematic plan views showing specific examples of apertures 28 more specifically the apertures 28 provided in the n buried layer 12 may have a pattern of quadrangles uniformly arranged in a lattice configuration as illustrated in fig4 the apertures 28 may have a pattern of hexagons as illustrated in fig5 rhombi as illustrated in fig6.