Disclosed is a solid resol-type phenolic resin having: methylol groups and dimethylene ether bonds, as functional groups bound to phenolic nuclei; a content of methylol group, per 1 mol of the phenolic nuclei, of 0.8 mol or more and 1.3 mol or less; a content of dimethylene ether bond, per 1 mol of the phenolic nuclei, of 0.1 mol or less; a weight-average molecular weight of a tetrahydrofuran-soluble fraction, measured by gel permeation chromatography (GPC), of 800 or larger and 4,000 or smaller; and a content of mononuclear phenolic compound of 10% by weight or less.