A semiconductor device manufacturing method comprising: a step of forming grooves in an upper surface of a wafer of a compound semiconductor material with a blade or by etching; a laser dicing step of forming through holes (201,202) in the wafer by performing laser dicing on the portions of the wafer in which the grooves are formed, as seen in plan, with portions of the grooves left as a side surface upper portion on both sides of the through holes (201, 202), the wafer being separated by the laser dicing into individual devices (200, 204, 206) formed of the compound semiconductor material with the side surface upper portion extending along the entire perimeter of each individual device (200, 204, 206), wherein upper surfaces of the individual devices (200, 204, 206) correspond to the upper surface of the wafer, and wherein the lower surfaces of the individual devices (200, 204, 206) correspond to a lower surface of the wafer, wherein the surface roughness of the side surface upper portion of the individual devices (200, 204, 206), which is a slanting surface, is lower than the surface roughness of a side surface lower portion of the individual devices (200, 204, 206) due to formation of molten material on the side surface lower portion as a result of melting of the compound semiconductor material during the laser dicing; a die bonding step of bonding a mount substrate and a lower surface of an individual device to each other with an adhesive, wherein a part of the adhesive climbs up on the side surface lower portion without reaching the side surface upper portion, wherein the surface roughness of the side surface upper portion of the individual device (200, 204, 206) being lower than the surface roughness of the side surface lower portion results in preventing that the adhesive climbing up on the side surface of the device (200, 204, 206) during the die bonding step reaches the device upper surface; and an adhesive curing step of curing the adhesive to obtain the semiconductor device. a step of forming grooves in an upper surface of a wafer of a compound semiconductor material with a blade or by etching; a laser dicing step of forming through holes (201,202) in the wafer by performing laser dicing on the portions of the wafer in which the grooves are formed, as seen in plan, with portions of the grooves left as a side surface upper portion on both sides of the through holes (201, 202), the wafer being separated by the laser dicing into individual devices (200, 204, 206) formed of the compound semiconductor material with the side surface upper portion extending along the entire perimeter of each individual device (200, 204, 206), wherein upper surfaces of the individual devices (200, 204, 206) correspond to the upper surface of the wafer, and wherein the lower surfaces of the individual devices (200, 204, 206) correspond to a lower surface of the wafer, wherein the surface roughness of the side surface upper portion of the individual devices (200, 204, 206), which is a slanting surface, is lower than the surface roughness of a side surface lower portion of the individual devices (200, 204, 206) due to formation of molten material on the side surface lower portion as a result of melting of the compound semiconductor material during the laser dicing; a die bonding step of bonding a mount substrate and a lower surface of an individual device to each other with an adhesive, wherein a part of the adhesive climbs up on the side surface lower portion without reaching the side surface upper portion, wherein the surface roughness of the side surface upper portion of the individual device (200, 204, 206) being lower than the surface roughness of the side surface lower portion results in preventing that the adhesive climbing up on the side surface of the device (200, 204, 206) during the die bonding step reaches the device upper surface; and an adhesive curing step of curing the adhesive to obtain the semiconductor device.