A monitoring apparatus for monitoring a raw material tank monitors the temperature of the raw material tank when the temperature of the raw material tank storing a solid or liquid raw material is raised to a set temperature by a heating unit. The monitoring apparatus includes: a temperature determination unit configured to determine whether the temperature has reached a stable range including the set temperature, and determine whether the temperature has deviated from the stable range; and a setting unit configured to set the set temperature of the heating unit to 0° C. when a predetermined timeout time has elapsed from a time point at which the temperature determination unit determined that the temperature deviated from the stable range.