The present invention relates to a soft capsule which is easily disintegrated in the stomach, wherein the contents thereof are not easily leaked at the time of mastication, which is obtained by providing a soft capsule comprising (2R)-2-propyloctanoic acid or a salt thereof with at least one property, preferably all properties, selected from (A) wherein it has a strength of 150 to 400 N by a cracking test; (B) wherein it has a disintegration time of 3 to 10 minutes by the disintegration test stipulated in Japanese Pharmacopoeia; (C) wherein the capsule shell has a shell thickness of 0.05 to 0.50 mm; (D) wherein the capsule shell has a first seam thickness of 0.10 to 0.55 mm; (E) wherein the capsule shell has a second seam thickness of 0.05 to 0.50 mm; (F) wherein the capsule shell has a water content of 5.0 to 9.0%.