A male member, comprising: a tubular member in which a flow path for carrying a liquid substance is formed; and a cover that covers at least a tip of the tubular member, wherein a lateral hole that communicates with the flow path is formed in an outer peripheral surface of the tubular member, the cover includes an outer peripheral wall that can be deformed elastically by compression and a head part that is provided at one end of the outer peripheral wall, the head part includes an interior cavity into which the tip of the tubular member is inserted, a slit that penetrates the head part is formed in an innermost part of the interior cavity, when the head part is displaced with respect to the tubular member so that the outer peripheral wall is deformed by compression, the tubular member penetrates the slit and the lateral hole is exposed from the head part, when the tubular member is pulled out from the slit, negative pressure corresponding to an increase in the capacity of the space is generated in the space and characterised in that in a state where the outer peripheral wall is not deformed by compression, an inner peripheral surface of the interior cavity of the head part contacts closely with the outer peripheral surface of the tubular member so as to block the lateral hole, and the tip of the tubular member and the innermost part of the interior cavity are spaced apart from each other, an airtight space is formed between the tip of the tubular member and the innermost part of the interior cavity, and a top part protrudes from an upper surface of the head part via a neck, and the slit is formed in the top part. a tubular member in which a flow path for carrying a liquid substance is formed; and a cover that covers at least a tip of the tubular member, wherein a lateral hole that communicates with the flow path is formed in an outer peripheral surface of the tubular member, the cover includes an outer peripheral wall that can be deformed elastically by compression and a head part that is provided at one end of the outer peripheral wall, the head part includes an interior cavity into which the tip of the tubular member is inserted, a slit that penetrates the head part is formed in an innermost part of the interior cavity, when the head part is displaced with respect to the tubular member so that the outer peripheral wall is deformed by compression, the tubular member penetrates the slit and the lateral hole is exposed from the head part, when the tubular member is pulled out from the slit, negative pressure corresponding to an increase in the capacity of the space is generated in the space and characterised in that in a state where the outer peripheral wall is not deformed by compression, an inner peripheral surface of the interior cavity of the head part contacts closely with the outer peripheral surface of the tubular member so as to block the lateral hole, and the tip of the tubular member and the innermost part of the interior cavity are spaced apart from each other, an airtight space is formed between the tip of the tubular member and the innermost part of the interior cavity, and a top part protrudes from an upper surface of the head part via a neck, and the slit is formed in the top part.