An ice maker is provided that varies an amount of heat transferred between an ice making member connected to a cooling unit and water being in direct or indirect contact with the ice making member according to portions of the ice making member, and producing ice in various forms including rounded ice without edges, especially spherical ice, on the ice making member, the ice maker including a cooling unit performing cooling; at least one ice making member connected to the cooling unit and being in direct or indirect contact with water to allow ice to be produced thereon; with an amount of heat transferred between the ice making member and the water being in direct or indirect contact with the ice making member varies according to portions of the ice making member, such that ice is produced in various forms on the ice making member.