There is provided a plastic ampule that can easily discharge remaining content liquid by a removal operation of shaking the plastic ampule before use so as to drop the remaining content liquid into a body portion even when the content liquid remains in a hallow portion of a head portion, and that shows excellent handling performance when the plastic ampule is unsealed. A plastic ampule comprises a body portion, a head portion 6 formed continuously to a mouth portion 3 of the body portion via a cut-off portion 10, and a knob portion 9 formed continuously to the head portion 6, wherein the plastic ampule is unsealed by twisting the knob portion 9 with fingers and cutting the head portion 6 off the mouth portion 3, and a hollow portion 8 in the head portion 6 is formed to have a bowl shape. The hollow portion 8 having a bowl shape makes possible to readily discharge the content liquid remaining in the hollow portion 8, makes possible to easily unseal the plastic ampule, and prevents the content liquid remaining in the hollow portion 8 from scattering at the time of unsealing.