An eyepiece system configured to be positioned between an image surface and an eye point, comprising: a first lens group in which a lens having a negative refractive power and a lens having a positive refractive power are joined, the first lens group as a whole having a positive refractive power; a second lens group, the second lens group including a lens having a positive refractive power, a third lens group that comprises a lens having a positive refractive power, wherein the first lens group, the second lens group and the third lens group are provided in that order in a direction from the image surface to the eye point, and at least one diffraction optical element, the diffraction optical element including a first diffractive element piece having a first diffractive optical surface, and a second diffractive element piece having a second diffractive optical surface, the first diffractive element piece and the second diffractive element piece being arranged so that the first diffractive optical surface and the second diffractive optical surface face each other, and the following conditional expressions being satisfied: when DH1 ≤ DH2, DH 1 / DH 1 H 2 ≤ 0.5 when DH1 > DH2, DH 2 / DH 1 H 2 ≤ 0.5 where DH1H2 is the absolute value of the distance on an optical axis of the eyepiece system between a front principal point and a rear principal point of the eyepiece system, DH1 is the absolute value of a distance on the optical axis between a front principal point and the first diffractive optical surface of the eyepiece system positioned between the image surface and the eye point, and DH2 is the absolute value of a distance on the optical axis between a rear principal point and the first diffractive optical surface of the eyepiece system positioned between the image surface and the eye point. a first lens group in which a lens having a negative refractive power and a lens having a positive refractive power are joined, the first lens group as a whole having a positive refractive power; a second lens group, the second lens group including a lens having a positive refractive power, a third lens group that comprises a lens having a positive refractive power, wherein the first lens group, the second lens group and the third lens group are provided in that order in a direction from the image surface to the eye point, and at least one diffraction optical element, the diffraction optical element including a first diffractive element piece having a first diffractive optical surface, and a second diffractive element piece having a second diffractive optical surface, the first diffractive element piece and the second diffractive element piece being arranged so that the first diffractive optical surface and the second diffractive optical surface face each other, and the following conditional expressions being satisfied: when DH1 ≤ DH2, DH 1 / DH 1 H 2 ≤ 0.5 when DH1 > DH2, DH 2 / DH 1 H 2 ≤ 0.5 where DH1H2 is the absolute value of the distance on an optical axis of the eyepiece system between a front principal point and a rear principal point of the eyepiece system, DH1 is the absolute value of a distance on the optical axis between a front principal point and the first diffractive optical surface of the eyepiece system positioned between the image surface and the eye point, and DH2 is the absolute value of a distance on the optical axis between a rear principal point and the first diffractive optical surface of the eyepiece system positioned between the image surface and the eye point. when DH1 ≤ DH2, DH 1 / DH 1 H 2 ≤ 0.5 when DH1 > DH2, DH 2 / DH 1 H 2 ≤ 0.5 where DH1H2 is the absolute value of the distance on an optical axis of the eyepiece system between a front principal point and a rear principal point of the eyepiece system, DH1 is the absolute value of a distance on the optical axis between a front principal point and the first diffractive optical surface of the eyepiece system positioned between the image surface and the eye point, and DH2 is the absolute value of a distance on the optical axis between a rear principal point and the first diffractive optical surface of the eyepiece system positioned between the image surface and the eye point. where DH1H2 is the absolute value of the distance on an optical axis of the eyepiece system between a front principal point and a rear principal point of the eyepiece system, DH1 is the absolute value of a distance on the optical axis between a front principal point and the first diffractive optical surface of the eyepiece system positioned between the image surface and the eye point, and DH2 is the absolute value of a distance on the optical axis between a rear principal point and the first diffractive optical surface of the eyepiece system positioned between the image surface and the eye point.