We have succeeded in synthesizing vertically aligned thin multi-walled carbon nanotubes (VA thin-MWCNTs) by a catalytic chemical vapor deposition (CCVD) method onto Fe/Al thin film deposited on a Si wafers using an optimum amount of hydrogen sulfide ($H_2S$) additive. Scanning electron microscope (SEM) images revealed that the as-synthesized CNT arrays were vertically well-oriented perpendicular to the substrate with relatively uniform length. Transmission electron microscope (TEM) observations indicated that the as-grown CNTs were nearly catalyst-free thin-MWCNTs with small outer diameters of less than 10nm. The average wall number is about 5. We suggested a possible growth mechanism of the VA thin-MWCNT arrays. The VA thin-MWCNTs showed a low turn-on electric field of about $1.1;V/{mu}m$ at a current density of $0.1;{mu}A/cm^2$ and a high emission current density about $2.5;mA/cm^2$ at a bias field of $2.7;V/{mu}m$. Moreover, the VA thin-MWCNTs presented better field emission stability without degradation over 20 hours (h) at the emission current density of about $1;mA/cm^2$.