The present invention is a sealing material composition comprising a moisture absorbent, and a sealing resin having a weight average molecular weight of 50,000 to 1,000,000, the moisture absorbent comprising a compound that comprises a repeating unit represented by a formula (1), and a sealing sheet, and an electronic device member, and an electronic device. The sealing material composition according to the present invention makes it possible to easily produce a sealing sheet that exhibits excellent transparency, an excellent water vapor barrier capability, and high adhesion, and the sealing sheet according to the present invention exhibits excellent transparency, an excellent water vapor barrier capability, and high adhesion, and may suitably be used to seal an organic EL device and the like, and the electronic device member and the electronic device according to the present invention rarely deteriorate, and exhibit excellent long-term reliability.