Problem: To provide a material and a method for efficient and inexpensive extraction of rare metals that are included in urban minerals. Solution: A method for the extraction of lanthanoid elements and actinoid elements, said method comprising: an adsorption process wherein a metal-dissolved solution containing a target metal selected from lanthanoid elements and actinoid elements is made to come into contact with porous structures that carry metal-adsorbent compounds that are adsorbent to target metal ions so that the target metal ions in said solution are adsorbed by said metal-adsorbent compounds; and a target metal separation process wherein said porous structures are made to come into contact with a back-extraction solution so that the target metal ions that are adsorbed by said metal-absorbent compounds are transported to the back-extraction solution.