We have developed a scanning electron microscope (SEM) equipped with a chemical vapor deposition system to investigate the growth processes and bundling processes of single-walled carbon nanotubes (SWNTs). The SWNT growth and in-situ SEM observation were performed on planar and micro-pillar-patterned substrates. Even an isolated SWNT could be observed using the enhanced secondary electron emission due to electron-beam-induced-current on insulator, or when it was suspended between pillar structures. On the planer substrate, SWNT grows upward from the surface in the initial growth stage, but falls to the surface in the later stage. On the patterned substrate, it forms a bridge between pillars in the initial growth stage, and then bundles with other SWNTs in the later stage. Understanding the growth mechanism of SWNTs is essential for the control of their diameter and chirality of them, and useful for the assembly of new SWNT architectures.