A specimen kit for enclosing a specimen is described, including a first substrate, a second substrate and a sealant. The first substrate has a first observation window at which a thickness thereof is smaller than that of the other parts thereof. The second substrate has a second observation window at which a thickness thereof is smaller than that of the other parts thereof, and is disposed on the first substrate such that the second observation window is aligned to the first observation window and an interval is present between the first and the second substrates. The sealant is disposed between the first and the second substrates and surrounds the first and the second observation windows to seal a space between fringes of the first and the second substrate, thus defining a specimen cell between the first and the second substrates.