Provided is a plastic ampule being handled suitably at the time of unsealing wherein remaining content liquid can be removed easily by performing a removal operation for dropping the remaining content liquid into a body portion by shaking the plastic ampule before use even when the content liquid remains in the hollow portion of a head portion. The plastic ampule comprises a body portion, a head portion (6) provided continuously to the mouth portion (3) of the body portion through a cut-off portion (10), and a knob portion (9) provided continuously to the head portion (6), the ampule being unsealed by twisting the knob portion (9) with fingers to cut the head portion (6) off the mouth portion (3), wherein the hollow portion (8) in the head portion (6) is formed in the shape of a bowl. Since the hollow portion (8) is formed in the shape of a bowl, content liquid remaining in the hollow portion (8) can be discharged easily, the plastic ampule can be unsealed easily, and the content liquid remaining in the hollow portion (8) is not scattered easily at the time of unsealing.
