To provide a novel cellulose-based compound, easily produced and bringing both ion conductivity and retainability of an electrolyte solution to be good, when applied to a gel-like electrolyte.

The carbonated cellulose-based compound has a structure in which at least a part of hydroxy groups of a hydroxyalkylcellulose having repeating units expressed by formula (1) [wherein n is an integer of 2; R1 to R6 each independently expresses H or a group expressed by (R7O)m (wherein R7 expresses a lower alkylene group; m is an integer of 1)] are substituted with a group expressed by -OC(=O)OR8 (wherein R8 denotes an alkyl group, a group in which an ether group is introduced in the alkyl chain or an aromatic group, each of which may be substituted and has 12C).