Attachment structure of glow plug

A first glow plug (100) and second through fourth glow plugs (200) are attached to an engine head (1). Each glow plug (100, 200) includes a plug body (700). The first glow plug (100) includes a pressure sensor (300), and is independently connected to a ring crimp terminal (400), which is separated from other glow plugs (200). Thus, a mechanical vibration due to a connecting bar (2) deflection between the second through fourth glow plugs (200) does not influence the first glow plug (100) including the pressure sensor (300).