Joint structure of structural members

A joint structure, comprising:

• a male-side joint,
• a female-side joint,
• said male-side joint has a first contacting surface, a second contacting surface which continues from a back side of the first contacting surface and extends at an angle of less than 90.degree. with respect to the first contacting surface, and a third contacting surface which continues from a front side of the first contacting surface and extends at an angle of 270.degree. or more with respect to the first contacting surface,
• said female-side joint has a first, a second, and a third contacted surface which correspond to said first, second, and third contacting surfaces of the male-side joint, respectively, these contacted surfaces are shaped so as to closely correspond to the first, second, and third contacting surfaces,
• a fastener for fastening said male-side joint to said female-side joint when the first, second, and third contacting surfaces of the male-side joint are put close to the first, second, and third contacted surfaces of the female-side joint,
• wherein said male-side joint has left and right sidewalls extending perpendicularly from both sides of said first, second, and third contacting surfaces, and a projected wall which projects from at least one of said first, second, and third contacting surfaces,
• the female-side joint has left and right sidewalls extending perpendicularly from both sides of the first, second, and third contacted surfaces, and a projected wall which projects from at least one of the first, second, and third contacted surfaces, and
• when said female-side joint is put closely on said male-side joint, the projected wall of said male-side joint is engaged with one of the left and right sidewalls of said female-side joint where the female-side joint projected wall is not provided, and the projected wall of said female-side joint is engaged with one of the left and right sidewalls of said male-side joint where the male-side joint projected wall is not provided.