A protection cap (13) of a protection device (1) is mounted on a mounting portion (10) by means of a hinge part (11). The protection cap (13) is set at a separation position when the hinge part (11) is in a first posture and is set at an inclination position when the hinge part (11) is in a second posture. A flexing part (12) undergoes elastic deformation, at the time when the protection cap (13) set at the inclination position is pressed to a protection position side, to cause the protection cap (13) to rotate from the inclination position to the protection position for protecting an injection needle (21) entirely.保護具(1)的保護蓋部(13)係透過樞紐部(11)而被安裝在安裝部(10)，保護蓋部(13)係當樞紐部(11)位於第1姿勢時，即位於分離位置，當樞紐部(11)位於第2姿勢時，則位於傾斜位置。可撓部(12)係當位於傾斜位置的保護蓋部(13)被按壓在保護位置側時，藉由作彈性變形，使保護蓋部(13)由傾斜位置旋動至保護注射針(21)全體的保護位置。
