How can I open Step Statement Editor in Ver.24.0.9?

Draft7a.asc

I apologize for the confusion. I need to correct myself.

The Step Statement Editor does not open only in the case of ".step temp."

For the ".step param" case, I was able to open the Step Statement Editor by right-clicking with the mouse.

(Corrected)
Hello HiroYama, I see what you are saying, the ".step temp" edit functionality no longer works in version 24 (up to 24.0.9) -- we will get this working in a future revision.  For the time being, you can open the .step editor (or the other "helper" editors), by right-clicking within the "Edit Text on the Schematic" dialog -> Help Me Edit.

Understood!
Thank you for your help.

Draft7b.asc

When I executed ".step param temp," it performed several sweeps; however, the actual temperature parameters were not being swept.

On the other hand, I was successful in opening the Step Statement Editor for ".step temp."
The Name of the parameter sweep is set to <global temp> there.

How should I describe " .step param XXXXX" for temperature parameter sweep ?

You are absolutely correct, my first response was incorrect -- I have now corrected it. 

".step temp" is the correct format.  We will fix the editor dialog to open automatically for ".step temp" directives in a future revision of LTspice.

Thank you. I appreciate your clarification and will await your revised version.