We have developed an easy-to-use method to separate metallic and semiconducting single-wall carbon nanotubes (SWCNTs) using agarose gel. The most effective separation was realized by a simple procedure in which a piece of gel containing SWCNTs was frozen, thawed, and squeezed with the fingers (Figure). This process does not need any special equipment other than a domestic freezer and affords a solution containing metallic SWCNTs and leaves a gel containing semiconducting SWCNTs. The method is so simple that we can easily proceed to the automation and scaling up of the process. This high-yield, low-cost, and scalable method could be suited for the industrial production of metallic and semiconducting SWCNTs, facilitating basic and applied research on SWCNT electronics.