A thermally expandable microcapsule, which shows excellent heat resistance and a high expansion ratio and thereby can be suitably used for molding processes involving high shearing force, such as kneading molding, calender molding, extrusion molding, and injection molding. The thermally expandable microcapsule also provides a foamed product using the thermally expandable microcapsule. The thermally expandable microcapsule contains a shell made of a polymer; and a volatile expansion agent as a core agent encapsulated in the shell, the storage elastic modulus (E′) of the shell at a temperature of 200° C. and a frequency of 10 Hz being 1×105 N/m2 or more, the storage elastic modulus (E′) of the shell at a temperature of 250° C. and a frequency of 10 Hz being 1×105 N/m2 or more, and a maximum displacement amount measured by thermomechanical analysis being 300 μm or more.