Provided is a steel cord having both shape stability and durability. A steel cord (1) is obtained by bundling five steel core wires (2), which are arrayed in parallel with one another in a plane, into a unitary body by means of an adhesive (3) having a thickness Ad of less than 15 µm. Each of the core wires (2) constituting the steel cord (1) has a diameter d of less than 0.45 mm, and spacing Gd between the core wires (2) is less than 20 µm. The core wires (2) used have a free coil diameter D that is greater than wire diameter d thereof by 750 times or more.