A foil bearing (30, 101), comprising: a tubular foil holder (31, 110); and a plurality of foils (32, 120) arrayed on an inner peripheral surface (31a, 111) of the tubular foil holder (31, 110) in a circumferential direction of the tubular foil holder (31, 110), the plurality of foils (32, 120) being held on the tubular foil holder (31, 110) under a state in which both circumferential ends of each of the plurality of foils (32, 120) are held in contact with the tubular foil holder (31, 110), the plurality of foils (32, 120) being held on the tubular foil holder (31, 110) under a state in which the plurality of foils are movable relative to the tubular foil holder (31, 110) in the circumferential direction, wherein the tubular foil holder (31, 110) has a plurality of grooves (31b, 114) formed in the inner peripheral surface (31a, 111) of the tubular foil holder (31, 110), wherein each of the plurality of foils (32, 120) comprises: a body portion (32a, 121) having a bearing surface; an insertion portion (32e, 122) formed at one circumferential end portion of the each of the plurality of foils (32, 120); and a mounting portion 32g, 123) formed at another circumferential end portion of the each of the plurality of foils (32, 120), and wherein the insertion portion (32e, 122) of the each of the plurality of foils (32, 120) is inserted into each of the plurality of grooves (31b, 114), characterised in that the insertion portion (32e, 122) of each of the plurality of foils (32, 120) is mounted to the mounting portion (32g, 123) of an adjacent one of each of the plurality of foils (32, 120), and each of the grooves (31b, 114) provides an internal space allowing the insertion portion (32e, 122) of each of the plurality of foils (32, 120) to be curved so as to convex toward radially outward in each of the grooves (31b, 114). a tubular foil holder (31, 110); and a plurality of foils (32, 120) arrayed on an inner peripheral surface (31a, 111) of the tubular foil holder (31, 110) in a circumferential direction of the tubular foil holder (31, 110), the plurality of foils (32, 120) being held on the tubular foil holder (31, 110) under a state in which both circumferential ends of each of the plurality of foils (32, 120) are held in contact with the tubular foil holder (31, 110), the plurality of foils (32, 120) being held on the tubular foil holder (31, 110) under a state in which the plurality of foils are movable relative to the tubular foil holder (31, 110) in the circumferential direction, wherein the tubular foil holder (31, 110) has a plurality of grooves (31b, 114) formed in the inner peripheral surface (31a, 111) of the tubular foil holder (31, 110), wherein each of the plurality of foils (32, 120) comprises: a body portion (32a, 121) having a bearing surface; an insertion portion (32e, 122) formed at one circumferential end portion of the each of the plurality of foils (32, 120); and a mounting portion 32g, 123) formed at another circumferential end portion of the each of the plurality of foils (32, 120), and a body portion (32a, 121) having a bearing surface; an insertion portion (32e, 122) formed at one circumferential end portion of the each of the plurality of foils (32, 120); and a mounting portion 32g, 123) formed at another circumferential end portion of the each of the plurality of foils (32, 120), and wherein the insertion portion (32e, 122) of the each of the plurality of foils (32, 120) is inserted into each of the plurality of grooves (31b, 114), characterised in that the insertion portion (32e, 122) of each of the plurality of foils (32, 120) is mounted to the mounting portion (32g, 123) of an adjacent one of each of the plurality of foils (32, 120), and each of the grooves (31b, 114) provides an internal space allowing the insertion portion (32e, 122) of each of the plurality of foils (32, 120) to be curved so as to convex toward radially outward in each of the grooves (31b, 114).