Waste heat recovery equipment comprising: an exhaust gas economizer which is configured to generate main steam by recovering heat from exhaust gas discharged from an internal combustion engine main body; a steam turbine which is configured to be mainly driven by the main steam derived from the exhaust gas economizer; an organic fluid heat exchanger which is configured to generate vapor of an organic fluid by recovering heat from a low-temperature heat source having a temperature lower than a temperature at which heat is recovered in the exhaust gas economizer; an organic fluid turbine which is configured to be driven by the vapor of the organic fluid generated in the organic fluid heat exchanger; a generator which is configured to generate electric power by an output from at least one of the steam turbine and the organic fluid turbine; an auxiliary boiler which is configured to generate auxiliary steam by using combustion heat of fuel; and a control unit; characterized in that the control unit is configured to control a burner of the auxiliary boiler to ignite the burner to generate auxiliary steam in a case in which a pressure value detected by a pressure sensor which is configured to detect a pressure of the main steam generated in the exhaust gas economizer reaches a value equal to or less than a threshold value, and the auxiliary steam generated in the auxiliary boiler is supplied to the steam turbine, and the threshold value is a predetermined value determined on the basis of the minimum pressure at which the steam turbine is capable of being independently operated by the main steam which is supplied from the exhaust gas economizer; and in that a rotary shaft of the organic fluid turbine is connected to a rotary shaft of the steam turbine through a rotary shaft of the generator or a rotary shaft of a speed reducer, and the control unit is configured to perform a control with the steam turbine as a master and the organic fluid turbine as a slave. an exhaust gas economizer which is configured to generate main steam by recovering heat from exhaust gas discharged from an internal combustion engine main body; a steam turbine which is configured to be mainly driven by the main steam derived from the exhaust gas economizer; an organic fluid heat exchanger which is configured to generate vapor of an organic fluid by recovering heat from a low-temperature heat source having a temperature lower than a temperature at which heat is recovered in the exhaust gas economizer; an organic fluid turbine which is configured to be driven by the vapor of the organic fluid generated in the organic fluid heat exchanger; a generator which is configured to generate electric power by an output from at least one of the steam turbine and the organic fluid turbine; an auxiliary boiler which is configured to generate auxiliary steam by using combustion heat of fuel; and a control unit; characterized in that the control unit is configured to control a burner of the auxiliary boiler to ignite the burner to generate auxiliary steam in a case in which a pressure value detected by a pressure sensor which is configured to detect a pressure of the main steam generated in the exhaust gas economizer reaches a value equal to or less than a threshold value, and the auxiliary steam generated in the auxiliary boiler is supplied to the steam turbine, and the threshold value is a predetermined value determined on the basis of the minimum pressure at which the steam turbine is capable of being independently operated by the main steam which is supplied from the exhaust gas economizer; and in that a rotary shaft of the organic fluid turbine is connected to a rotary shaft of the steam turbine through a rotary shaft of the generator or a rotary shaft of a speed reducer, and the control unit is configured to perform a control with the steam turbine as a master and the organic fluid turbine as a slave.