The modern shell gallery structures, which characterized by optimallymatched parameters of geometric and material are very sensitive to the loss of stability. The designer is required in the design process to check it in several phases of work. This is not only checking the operation phase but also in transport and installation phase. Operating scheme of shell galleries, them shipped elements in the assembly phase, sometimes have a completely different character. In this paper the authors present the problem of stability of the shell gallery in the assembly phase. For example, realized the construction of a conveyor gallery, authors present the need to use additional elements to protect the structure against loss of stability. The paper contains analysis of the stability of shell structure of the conveyor gallery. Keywords: stability, steel shell, conveyor gallery, steel construction, assembly.