A subsampling device comprising: a flange member in which a through hole to be in communication with a housing space of a sample storing container is formed, and said flange member is formed with at least one first pressure adjusting passage in communication with the through hole, and said flange member is coupled to a rear end face of the sample storing container; a coupling member in which a cavity to be in communication with the through hole of the flange member is formed, and which has a first end that is couplable to the through hole of the flange member; a cylindrical casing which has a front end connected to a second end of the coupling member, wherein said cylindrical casing comprises a ball valve disposed at a nearby location to the front end, and formed with at least one second pressure adjusting passage formed at a nearby location to a rear end of the cylindrical casing and in communication with an internal space of the cylindrical casing; a sampling pipe which is provided with a partition wall that divides the internal space of the cylindrical casing into a front space and a rear space, wherein the sampling pipe comprises a collecting blade formed at a front end of the sampling pipe, and wherein the sampling pipe slides in the internal space of the cylindrical casing; and a sample container which is connectable to the first end of the coupling member to replace the flange member, wherein the sliding sampling pipe causes the collecting blade to contact a sample in the sample storing container to perform subsampling on the sample so as to be held at the front end of the sampling pipe when the coupling member is coupled to the through hole of the flange member, and the sample having undergone the subsampling is transferred to the sample container when the sample container is attached to the coupling member in place of the flange member. a flange member in which a through hole to be in communication with a housing space of a sample storing container is formed, and said flange member is formed with at least one first pressure adjusting passage in communication with the through hole, and said flange member is coupled to a rear end face of the sample storing container; a coupling member in which a cavity to be in communication with the through hole of the flange member is formed, and which has a first end that is couplable to the through hole of the flange member; a cylindrical casing which has a front end connected to a second end of the coupling member, wherein said cylindrical casing comprises a ball valve disposed at a nearby location to the front end, and formed with at least one second pressure adjusting passage formed at a nearby location to a rear end of the cylindrical casing and in communication with an internal space of the cylindrical casing; a sampling pipe which is provided with a partition wall that divides the internal space of the cylindrical casing into a front space and a rear space, wherein the sampling pipe comprises a collecting blade formed at a front end of the sampling pipe, and wherein the sampling pipe slides in the internal space of the cylindrical casing; and a sample container which is connectable to the first end of the coupling member to replace the flange member, wherein the sliding sampling pipe causes the collecting blade to contact a sample in the sample storing container to perform subsampling on the sample so as to be held at the front end of the sampling pipe when the coupling member is coupled to the through hole of the flange member, and the sample having undergone the subsampling is transferred to the sample container when the sample container is attached to the coupling member in place of the flange member.