A cooling apparatus comprising: a base plate for receiving a heat load from one or more electric components, an evaporator with a first surface in thermal contact with a surface of the base plate for transferring said heat load into a first fluid in the evaporator in an operating state of the cooling apparatus, wherein the evaporator comprises a porous structure having capillary pores, a condenser for receiving first fluid from a first end of the evaporator and for dissipating heat from the first fluid, and a compensation chamber extending along a second surface of the evaporator, which is an opposite surface to the first surface, the compensation chamber receiving first fluid from the condenser such that pores opening up into the second surface of the evaporator are provided with first fluid, wherein the cooling apparatus is a capillary loop heat pipe, and wherein the porous structure of the evaporator is a porous aluminum structure having capillary pores and larger sized evaporator channels extending through the evaporator between a second end and the first end of the evaporator, characterized in that the evaporator channels are embedded in the evaporator at a location between the first surface and the second surface and arranged in more than one layer such that each layer includes a plurality of evaporator channels, and the cooling apparatus comprises a chamber in a first end of the apparatus which is in fluid communication with the first end of the evaporator and with a first end of the condenser for passing first fluid from the evaporator to the condenser with minimized pressure losses, a cross-sectional flow area of the chamber is of similar size or larger than the combined cross-sectional flow area of all the evaporator channels, said chamber is delimited by the housing, the evaporator and the condenser. a base plate for receiving a heat load from one or more electric components, an evaporator with a first surface in thermal contact with a surface of the base plate for transferring said heat load into a first fluid in the evaporator in an operating state of the cooling apparatus, wherein the evaporator comprises a porous structure having capillary pores, a condenser for receiving first fluid from a first end of the evaporator and for dissipating heat from the first fluid, and a compensation chamber extending along a second surface of the evaporator, which is an opposite surface to the first surface, the compensation chamber receiving first fluid from the condenser such that pores opening up into the second surface of the evaporator are provided with first fluid, wherein the porous structure of the evaporator is a porous aluminum structure having capillary pores and larger sized evaporator channels extending through the evaporator between a second end and the first end of the evaporator, characterized in that the evaporator channels are embedded in the evaporator at a location between the first surface and the second surface and arranged in more than one layer such that each layer includes a plurality of evaporator channels, and the cooling apparatus comprises a chamber in a first end of the apparatus which is in fluid communication with the first end of the evaporator and with a first end of the condenser for passing first fluid from the evaporator to the condenser with minimized pressure losses, a cross-sectional flow area of the chamber is of similar size or larger than the combined cross-sectional flow area of all the evaporator channels, said chamber is delimited by the housing, the evaporator and the condenser.