A substrate transfer device includes an atmosphere introduction unit and an atmosphere exhaust unit provided at a top and a bottom portion of a main body of the device, respectively; and a substrate transfer mechanism provided between the atmosphere introduction unit and the atmosphere exhaust unit. The substrate transfer device further includes a downward flow forming unit provided, adjacent to the atmosphere introduction unit, to allow an atmosphere to be introduced through the atmosphere introduction unit and to downwardly flow through the substrate transfer mechanism and be exhausted through the atmosphere exhaust unit; and a gas ionizing unit for ionizing the atmosphere and a particle collecting unit for collecting particles included in the atmosphere, the gas ionizing unit and the particle collecting unit being sequentially provided in the direction in which the atmosphere downwardly flows, between the downward flow forming unit and the substrate transfer mechanism.