A power transmission device includes a power transmission unit transmitting electric power in a contactless manner to a power reception unit provided outside; and a power transmission-side shield formed in a hollow shape and provided so as to surround the power transmission unit. An electromagnetic wave can pass through a region on a side opposite to a region where the power reception unit is located across the power transmission-side shield. The power transmission-side shield is provided with a shield member on a side opposite to the power transmission unit across the power transmission-side shield.