To provide a guide apparatus in a boiler framing building method in which upon a boiler frame being built with the aid of a boiler framing building method where height work and field work can be reduced with an improvement of working efficiency and hence shortening of the term of works interval, resulting in an improvement of working quality, a floor block is prevented from being shaken owing to strong wind and earthquake, etc., and which serves to promote the work more smoothly.

A floor block 6 installed on an uppermost portion is lifted by a predetermined amount from the ground, and a floor block 6 installed under the foregoing floor block is assembled in the neighbourhood of the ground. Similarly in the following, lifting of a floor block 6 and assembling of a floor block 6 installed under the foregoing floor block 6 in the neighbourhood of the ground are repeated in order. Hereby, iron skeleton units located before and behind and left and right are completed and are anchored to a main column 3. Upon building the boiler frame a guide roller 17 that is capable of being rolled vertically along the main column 3 is disposed at opposite ends of the floor block 6 for transmitting the average load to the main column 3.