An object of the present invention is to provide a method for efficiently separating megakaryocytes and platelets produced from the megakaryocytes, and an instrument for efficiently separating megakaryocytes and platelets produced from the megakaryocytes. According to the present invention, a method for separating megakaryocytes and platelets, including a contact step of bringing a culture solution that contains at least megakaryocytes into contact with a substrate coated with a biocompatible polymer that adheres to the megakaryocytes via at least one of a VLA-4 integrin or a VLA-5 integrin; a culture step of culturing the megakaryocytes to produce platelets before and/or after the contact step; and a recovery step of recovering the culture solution after the contact step and the culture step is provided.