Substrate processing method

A substrate processing method comprising:

• a substrate holding step of holding a substrate horizontally;
• a processing liquid supply step of supplying a processing liquid containing a water, onto the horizontally held substrate;
• a substrate rotating step of rotating the horizontally held substrate;
• a liquid film forming step of supplying a low surface tension liquid having lower surface tension than water onto an upper surface of the horizontally held substrate while rotating the substrate at a first rotational speed, in order to replace the processing liquid on the substrate with the low surface tension liquid and form a liquid film of the low surface tension liquid on the upper surface of the substrate;
• a rotation decelerating step of decelerating rotation of the horizontally held substrate to a second rotational speed that is a lower speed than the first rotational speed while continuing the liquid film forming step, after the processing liquid on the substrate has been replaced with the low surface tension liquid having lower surface tension than water;
• an opening forming step of forming an opening in a center region of the liquid film on the substrate that rotates at the second rotational speed after completion of the liquid film forming step;
• and
• a liquid film removing step of removing the liquid film from the upper surface of the substrate by widening the opening,
• wherein the first rotational speed is a speed at which the processing liquid is spun off outward from the horizontally held substrate.