Disclosed is a connector assembly provided with a first connector having a tubular first connector body, a hollow needle supported inside the first connector body and a first sealing component that can be pierced by the hollow needle, and a second connector having a tubular second connector body and a second sealing component. The second sealing component is disposed in the second connector body, is attached to a first piercing section when inserted into the first connector body, and, in that state, is pierced by the hollow needle together with the first piercing section. The connector assembly is further provided with an operation restricting means which, when the second connector is inserted into the first connector, temporarily interrupts and restricts the insertion operation, but allows resumption of the insertion operation when the restriction is removed, and which, when the second connector is withdrawn from the first connector, temporarily interrupts and restricts the withdrawing operation, but allows resumption of the withdrawing operation when the restriction is removed.