A rocket fuel pump (P, R) including a rotating body mounted on a rotating shaft and pressure-feeding rocket fuel when the rotating body is rotationally driven by a drive source, the rocket fuel pump (P, R) comprising: a magnetic coupling which is configured to magnetically couple the rotating shaft and a drive shaft of the drive source, wherein the magnetic coupling includes a plurality of driven side magnets provided on the rotating shaft and a plurality of drive side magnets (7b, 7c, 7d) provided on the drive shaft of the drive source, the driven side magnets and the drive side magnets (7b, 7c, 7d) are permanent magnets, the driven side magnets are provided in an annular shape at a predetermined angular pitch around a rotation central axis (Lp) of the rotating shaft, and the drive side magnets (7b, 7c, 7d) have an annular shape with the same angular pitch as the driven side magnets, characterized in that the drive side magnets (7b, 7c, 7d) include: a plurality of main drive side magnets facing the driven side magnets in a radial direction of the rotating shaft and configured to have a polarity opposite to a polarity of the driven side magnets; and a plurality of sub drive side magnets (7c, 7d) disposed to sandwich the main drive side magnets in an extending direction of the rotating shaft and configured to have the same polarity as the driven side magnets, and in that the main drive side magnets and the driven side magnets have a similar length in an extending direction of a rotation central axes (Lp, Lt) of the rotating shaft and the drive shaft. a magnetic coupling which is configured to magnetically couple the rotating shaft and a drive shaft of the drive source, wherein the magnetic coupling includes a plurality of driven side magnets provided on the rotating shaft and a plurality of drive side magnets (7b, 7c, 7d) provided on the drive shaft of the drive source, the driven side magnets and the drive side magnets (7b, 7c, 7d) are permanent magnets, the driven side magnets are provided in an annular shape at a predetermined angular pitch around a rotation central axis (Lp) of the rotating shaft, and the drive side magnets (7b, 7c, 7d) have an annular shape with the same angular pitch as the driven side magnets, characterized in that the drive side magnets (7b, 7c, 7d) include: a plurality of main drive side magnets facing the driven side magnets in a radial direction of the rotating shaft and configured to have a polarity opposite to a polarity of the driven side magnets; and a plurality of sub drive side magnets (7c, 7d) disposed to sandwich the main drive side magnets in an extending direction of the rotating shaft and configured to have the same polarity as the driven side magnets, and in that the main drive side magnets and the driven side magnets have a similar length in an extending direction of a rotation central axes (Lp, Lt) of the rotating shaft and the drive shaft. a plurality of main drive side magnets facing the driven side magnets in a radial direction of the rotating shaft and configured to have a polarity opposite to a polarity of the driven side magnets; and a plurality of sub drive side magnets (7c, 7d) disposed to sandwich the main drive side magnets in an extending direction of the rotating shaft and configured to have the same polarity as the driven side magnets, and in that the main drive side magnets and the driven side magnets have a similar length in an extending direction of a rotation central axes (Lp, Lt) of the rotating shaft and the drive shaft.