To reduce ejection failure of a medium ejected to a loading part.

The medium ejection device (1) includes: an ejection member (2+11) for ejecting a medium (S) toward a loading part (31) in which the medium (S) is loaded while nipping the medium between a first rotary member (2) and a second rotary member (11); the second rotary member (11) having a conveying part (18) that is configured to be rotatable around a shaft (17) and is able to be in contact with the first rotary member (2), and a giving part (21), which is arranged at a position displaced in a shaft direction from the conveying part (18) and is configured to be rotatable around the shaft (17), for giving curvature to the medium (S) along the shaft direction by having larger distance from the shaft (17) to its circumference than that of the conveying part (18); and a contact part (22) that is provided on the circumference of the giving part (21) and contacts the medium (S) at an upstream end in an ejecting direction of the medium (S), which is ejected accompanying rotation of the ejection member (2+11).