The radial foil bearing (3) for supporting a rotary shaft (1) includes a cylindrical top foil (10) disposed to face the rotary shaft (1), a back foil (11) disposed on a radially outer side of the top foil (10), and a cylindrical bearing housing (12) accommodating the top foil (10) and the back foil (11). The back foil (11) is formed in a cylindrical shape using at least one back foil piece (11a). The back foil piece (11a) includes peak portions (11c) and valley portions (11b) which are alternately formed in a circumferential direction of the top foil (10) and is fixed to the bearing housing (12) at an intermediate portion between both end portions in a circumferential direction of the back foil piece.