To provide sink plates which are slidable without occurrence of mutual displacement from each other even in superimposed condition to secure excellent work environment: and to provide a sink unit including the same.

The sink unit 2 is provided with a pair of guiding faces 112a, 112b each set to a position midway in a depth direction of front and back inside wall surfaces 100a, 100b of a sink body 100 and extending along a horizontal direction. The plates 41, 42 disposed to be slidable on the guiding faces 112a, 112b respectively have movement restriction parts (a protruding part 301 and a notch part 302 of a protective cap 300) engaged with each other to join both of the plates to be prevented from being displaced in a horizontal direction of the sink body 100.