Disclosed is a vial adapter (10) provided with a fitting portion (72) which can be fitted into the head portion (13) of a vial (12), and a hollow needle (38) with a side hole (56). The base end portion of the needle (38) is provided with a stopper contact portion (60) which contacts the top surface (27) of a stopper (16) when the fitting portion (72) is fitted in the head portion (13) of the vial (12). When the fitting portion (72) is fitted in the head portion (13) of the vial (12), the stopper contact portion (60) contacts the top surface (27) of the stopper (16), and the fitting portion (72) is fixed to the head portion (13) of the vial (12) by means of a claw (76) engaging with the head portion (13) of the vial (12), and further, the region of the side hole (56) nearest the base end portion of the needle (38) is positioned either roughly at the bottom surface of the stopper (16) or inside of the stopper (16).
