A powder contains particles containing a water-soluble material and a water-insoluble material. When dependence on temperature of a storage elastic modulus and a loss elastic modulus of a cylindrical compact of the powder in a shear direction, the cylindrical compact having a diameter of 10 mm and a thickness of 1 mm, is measured with a rotational rheometer at an angular frequency of 1 Hz and a rate of temperature increase of 2° C./min, letting a temperature at which the storage elastic modulus is 1 MPa be T° C., the storage elastic modulus is always higher than the loss elastic modulus in a temperature range of T° C. to (T+10)° C.