To provide a base isolating apparatus, capable of effectively lengthening an inherent cycle on the base isolated object side by promoting the elastic deformation of an elastic body requested to have considerable rigidity for supporting the weight of the base isolated object, in response to the vibration of a base.

Air springs 12 for a vertical base isolating device 8, and laminated rubber 9 for a horizontal base isolating apparatus 7 are provided between a foundation 2 and a structure 4 on the foundation 2. Vertical and horizontal elastic springs 10 and 13 arranged in the compressed state in horizontal and vertical clearances C and V formed between the structure and the foundation, and elongated to return to natural length by the vertical and horizontal relative movement of the structure and foundation, so as to increase the respective vertical and horizontal elastic deformation quantities of the air springs and laminated rubber, are provided in parallel with the air springs 12 and laminated rubber 9, to promote the respective vertical and horizontal elastic deformation of the air springs and laminated rubber in the vertical and horizontal relative moving directions of the foundation and structure in response to the vertical and horizontal vibration of the foundation.