A direct-injection type diesel engine comprises a cylinder head (1) with a fuel injection nozzle (2) and a glow plug (3) attached thereto. The fuel injection nozzle (2) has a leading end opposed to a cylinder mid portion (4) and the glow plug (3) extends through an intake port wall portion (6) between the fuel injection nozzle (2) and an intake port (5). The glow plug (3) is inclined with respect to the fuel injection nozzle (2) by a predetermined angle (&thgr;1) and has a leading end inserted into the cylinder mid portion (4).