A brush seal device (100; 200; 500) having a brush portion in which a plurality of bristles are arranged and sealing in an axial direction between a housing and a rotational shaft, characterized in that said brush seal device comprises an inner circumferential brush seal part (101; 201) having an inner circumferential brush seal (120; 220), and an outer circumferential brush seal part (102; 202; 502) having an outer circumferential brush seal (140; 240; 540), wherein said inner circumferential brush seal (120; 220) comprises: an attachment section (122; 222) provided at an outer circumferential side; a brush portion (123; 223) in which a plurality of bristles (121; 221) are arranged from the attachment section (122; 222) to an inner circumferential direction; and a free end portion (125; 225) which is an inner-circumferential-side end portion of the brush portion (123; 223) and is arranged opposite to an outer circumferential surface of the rotational shaft so as to contact or be adjacent to the outer circumferential surface, and said outer circumferential brush seal (140; 240; 540) comprises: an attachment section (142; 242; 542) provided at an outer circumferential side; a brush portion (143; 243; 543) in which a plurality of bristles (141; 241; 541) are arranged from the attachment section (142; 242; 542) to an inner circumferential direction; and a free end portion (145; 245; 545) which is an inner-circumferential-side end portion of the brush portion (143; 243; 543) and is arranged opposite to an outer circumferential surface (111; 211) of the inner circumferential brush seal part (101; 201) so as to contact or be adjacent to the outer circumferential surface (111; 211). characterized in that said brush seal device comprises an inner circumferential brush seal part (101; 201) having an inner circumferential brush seal (120; 220), and an outer circumferential brush seal part (102; 202; 502) having an outer circumferential brush seal (140; 240; 540), wherein said inner circumferential brush seal (120; 220) comprises: an attachment section (122; 222) provided at an outer circumferential side; a brush portion (123; 223) in which a plurality of bristles (121; 221) are arranged from the attachment section (122; 222) to an inner circumferential direction; and a free end portion (125; 225) which is an inner-circumferential-side end portion of the brush portion (123; 223) and is arranged opposite to an outer circumferential surface of the rotational shaft so as to contact or be adjacent to the outer circumferential surface, and an attachment section (122; 222) provided at an outer circumferential side; a brush portion (123; 223) in which a plurality of bristles (121; 221) are arranged from the attachment section (122; 222) to an inner circumferential direction; and a free end portion (125; 225) which is an inner-circumferential-side end portion of the brush portion (123; 223) and is arranged opposite to an outer circumferential surface of the rotational shaft so as to contact or be adjacent to the outer circumferential surface, and said outer circumferential brush seal (140; 240; 540) comprises: an attachment section (142; 242; 542) provided at an outer circumferential side; a brush portion (143; 243; 543) in which a plurality of bristles (141; 241; 541) are arranged from the attachment section (142; 242; 542) to an inner circumferential direction; and a free end portion (145; 245; 545) which is an inner-circumferential-side end portion of the brush portion (143; 243; 543) and is arranged opposite to an outer circumferential surface (111; 211) of the inner circumferential brush seal part (101; 201) so as to contact or be adjacent to the outer circumferential surface (111; 211). an attachment section (142; 242; 542) provided at an outer circumferential side; a brush portion (143; 243; 543) in which a plurality of bristles (141; 241; 541) are arranged from the attachment section (142; 242; 542) to an inner circumferential direction; and a free end portion (145; 245; 545) which is an inner-circumferential-side end portion of the brush portion (143; 243; 543) and is arranged opposite to an outer circumferential surface (111; 211) of the inner circumferential brush seal part (101; 201) so as to contact or be adjacent to the outer circumferential surface (111; 211).