Washing machine and controlling method of washing machine

A washing machine comprising:

• a housing including a loading inlet open along a front direction;
• a tub to be positioned inside the housing;
• a door configured to open or close the loading inlet;
• a detergent supply device to be provided in a first space formed between the housing and an upper portion of a first side of the tub while the tub is positioned inside the housing, the detergent supply device configured to supply a detergent to the tub;
• a pump device configured to pump water inside the tub;
• a filter configured to filter water received from the pump device;
• and
• a filter discharge pipe through which the water having passed through the filter flows, the filter discharge pipe configured to guide the water to the tub or guide the water outside of the housing,
• wherein the filter is in a second space formed between the housing and an upper portion of a second side of the tub.