A cap unit is provided which provides improved convenience. The cap unit is attached in a detachable manner to a neck portion of a container main body, an upper portion of which is open. The cap unit includes a cap main body that blocks an upper opening of the container main body and in which a liquid flow spout is provided in an upper portion, and a lid that opens and closes the liquid flow spout in a state of being attached to the cap main body in a rotating manner using a hinge portion, in which a maintaining member maintains an open state of the lid at a position at which the lid opens the liquid flow spout is provided in the hinge portion.