The invention relates to a cooling arrangement for an electric appliance unit. The electric appliance unit (1) comprises a housing (2), inside which there area arranged electric and/or electronic components, such as relays, semiconductors and resistors, as well as their wiring and support structures. The electric appliance unit (1) can be attached by suitable fastening elements (3) to an electric control center together with other corresponding units. According to the invention, the cooling arrangement comprises a vertical cooling channel (5) fitted through the housing (2), through which cooling channel the cooling air is arranged to flow (a, b); in connection with said cooling channel (5), there is installed at least one device, device element or component with a high cooling demand, such as a high-power semiconductor (P).