To provide a vessel which is unnecessary for heating when sealing the vessel capable of sealing with a material of the quantity as small as possible even when the vessel is wide-mouthed, and capable of indicating that the vessel is unsealed when it is once unsealed.

A male screw 12 is provided on an outer circumference of a mouth 11 of the vessel, a projection 13 having an inclined surface leading from a screw groove to a thread and an end face cut-off toward the center is formed on a terminating end of the male screw 12, a female screw 15 is formed on an inner circumferential surface of a cap 14, a locking piece 16 hooked to the projection 13 is provided on the leader extension line of the female screw 15, the locking piece 16 is provided in a frame 18 weakly connected to a circumferential surface of the cap 14, and a pull-ring 19 is added to the frame 18 as necessary.