Cassette for housing one or more medical instrument (18) including a tray having at least one passage (20) for receiving said medical instrument, said tray having a rigid structure (12) and a resilient holding means (28) arranged to retain the medical instrument (18) within said passage, wherein the holding means is located remote from the upper surface, and the at least one passage is formed by the rigid structure (12) and the holding means such that the uppermost section (44) of the passage is formed by the rigid structure and at least a portion of the lower section (46) of the passage is formed by the holding means.
